Insulating Glass Unit Compression-Injection Coated Patch and Method

ABSTRACT

A method for applying a patch to a spacer discontinuity or other seal breach includes the step of applying pressure to the patch during the application of the patch to cause sealant carried by the patch to be injected into the spacer discontinuity. This step can be performed with or without the application of heat. Pressure is applied to the patch long enough to position the sealant entirely across the gap between the lites such that the sealant wets out against both interior glass surfaces. Pressure is also applied to the patch long enough to inject sealant into openings defining the discontinuity. A sealant is then applied over the entire patch. The structure of the patch and the patched IG unit are provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application claiming priority to U.S.application Ser. No. 15/256,122 filed Sep. 2, 2016, which claims thebenefit of U.S. Provisional Patent Application No. 62/214,704 filed Sep.4, 2015; the disclosures of both are incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE 1. Technical Field

The disclosure generally relates to insulating glass units and, moreparticularly, to devices and methods for sealing insulating glass units.Specifically, the disclosure relates to a patch and method of installinga patch at the joint of a spacer or other breaches in the seal in aninsulating glass unit.

2. Background Information

The fenestration industry recognizes the importance of achieving aneffective and enduring hermetic seal when manufacturing sealedinsulating glass (IG) units. The seal is needed to minimize airintrusion and/or gas fill loss over the service life of the IG unit inorder to optimize thermal insulation performance and durability.

The industry also recognizes the fact that any joint or discontinuity inan IG unit spacer is a break in the spacer's continuous seal which needsto be closed during production in order to provide the overall seal forthe unit. The most common discontinuity is the start/stop location ofthe spacer where the first end of the perimeter spacer starts and secondend of the perimeter spacer stops. These ends can touch each other or beclosely spaced. Examples of IG unit spacer joints or discontinuitiesinclude 1) an angled joint when the start/stop joint is in a corner, 2)a straight joint when the start/stop joint is in a straight side, and 3)a splice in the spacer itself at a location other than the spacerstart/stop application point. Examples of other seal breaches which needto be patched include capillary breather tube and wire insertion points,gas-fill holes and fasteners for internal IG components and the like.

The industry has published no general guidelines for closingdiscontinuities and other seal breaches. IG unit spacer discontinuitysealing has been customized depending on the specific spacer/sealantcombination. The common practice has simply been to wrap a cover overthe area to be patched. The typical cover has been either anadhesive-coated vapor barrier film or aluminum foil coated with PIB. Itwill be applied after one lite has been installed, then either before orafter the second lite has been installed. In some applications, thewrapped cover application alone has been found to be an unreliable andineffective seal. This cover helps to maintain the position of thespacer ends until the sealant is added to the outer channel.

BRIEF SUMMARY OF THE DISCLOSURE

The disclosure provides a method of sealing a spacer discontinuity in aninsulating glazing unit, a method of forming an insulating glazing unitwith a sealed spacer discontinuity, and an insulating glazing unithaving a sealed spacer discontinuity. These methods and the unitincludes a compression-injection patch that carries sealant and isapplied over the spacer discontinuity with pressure to inject thesealant of the patch into the discontinuity. The patch is completelycovered with sealant after installed. The methods can be performedmanually or as part of an automated system.

The objective of the compression-injection patch application inventionis to reliably, rapidly and cost effectively achieve an effective andenduring hermetic seal at each potential breach of the spacer seal of aninsulating glazing unit including spacer joints, spacer splices,capillary tube and wire insertion points, gas-fill holes and fastenerlocations (all referred to herein as spacer discontinuities) whenmanufacturing sealed insulating glass (IG) units. The seal is needed tominimize exterior air intrusion into the insulating chamber of the unitand gas fill loss from the insulating chamber of the unit over theservice life of the IG unit in order to optimize thermal insulationperformance and durability of the unit.

The disclosure also provides a tool that is used to apply the patch.

With respect to the loss of gas from an IG unit such as argon, theBritish and European Standards (BS EN) EN1279 Part 3 requirement is themost stringent. This standard is incorporated herein by reference. Topass, EN1279-3 requires less than 1% argon loss per year following unitweathering. The disclosure provides a patch and method for installing apatch that allows the IG unit to meet this requirement.

The disclosure provides a patch having a backing layer carrying asealant. The backing layer is engaged by the tool that applies pressureto the patch during the application process. The backing layer is aflexible material suitable for carrying sealant. A solid flexible filmcan be used for the backing layer. The film can be a polymer. Thesealant can be a polyisobutylene (PIB) in one configuration of thepatch. The exemplary configuration of the patch has a thickness of thePIB layer that provide enough sealant volume to be injected into thediscontinuity and to wet out to both glass lites across the spacerwidth.

The disclosure provides a method for applying a patch to a spacer jointor discontinuity or other seal breach wherein the method includes thestep of applying pressure during the application process to cause thesealant of the patch to be injected into the joint or breach. This stepcan be performed with or without the application of heat. With a manualhand tool, the typical time at room temperature is about five seconds.The pressure can be held for about twenty seconds. Pressure is applieduntil the desired result is achieved. Pressure is applied to the patchlong enough to position the sealant entirely across the gap between thelites such that the sealant wets out against both interior glasssurfaces. Pressure is also applied to the patch long enough to injectsealant into openings between the ends of the spacer that define thejoint or breach being patched.

The disclosure provides a method wherein the patch can be connected tothe spacer either before, during, or after the glass lites are attachedto the spacer. Regardless of when the patch is positioned, the pressureis applied after the glass lites are secured to the spacer.

The pressure can be applied with a tool that has a width that isslightly less wide than the space between the interior surfaces of theglass lites such that even pressure is applied across the patch and thespace for flow of sealant out around the tool is minimized. A tool witha notch that matches the corner (such as 90 degrees) is used for cornersand a straight tool or other custom shape is used for joints andbreaches located along a straight section of spacer. The tool headsthemselves may be heated or heat may be applied with a heat gun beforeor at the same time the pressure is applied.

The preceding non-limiting aspects, as well as others, are moreparticularly described below. A more complete understanding of theprocesses and equipment can be obtained by reference to the accompanyingdrawings, which are not intended to indicate relative size anddimensions of the assemblies or components thereof. In those drawingsand the description below, like numeric designations refer to componentsof like function. Specific terms used in that description are intendedto refer only to the particular structure of the embodiments selectedfor illustration in the drawings, and are not intended to define orlimit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of an insulating glass unit with thespacer defining a corner discontinuity at the upper left hand corner.

FIG. 2 is a section view taken along line 2-2 of FIG. 1.

FIG. 3 is an enlarged elevation view of the corner of FIG. 1 with apatch initially placed over the corner discontinuity.

FIG. 4 is an enlarged elevation view of the corner of FIG. 1 withexemplary tools that applied pressure to the patch to inject sealantinto the discontinuity of the spacer.

FIG. 5 is an enlarged elevation view of the corner of FIG. 1 with thesealant positioned over the applied patch.

Similar numbers refer to similar parts throughout the specification.

DETAILED DESCRIPTION OF THE DISCLOSURE

FIG. 1 depicts a front elevation view of an insulating glass unit 102that generally includes first and second glass lites 104 held apart by aspacer 106 disposed inwardly of the outer perimeter of glass lites 104to define an outer channel 108. Example configurations of spacer 106 canbe any of the configurations disclosed in U.S. Pat. No. 4,831,799 or6,581,341, both of which are incorporated herein by reference todisclose spacer structures, sealants, and adhesives. Other spacer 106configurations can be used such as the spacer configuration sold underthe TruPlas trademark (OHIM Registered Trademark 11,774,908)(http://www.edgetechig.co.uk/truplas.asp). The TruPlas® spacer is arigid, glass reinforced thermoplastic spacer. In the example depicted inthe drawings, spacer 106 has a flexible body that may be foam and may bedesiccated. A vapor barrier 110 can be fully or partially wrapped aboutthe sides of the spacer body. An adhesive 112 secures spacer 106 to theinwardly-facing surfaces of glass lites 104. Adhesive 112 can be anacrylic adhesive. Sealant 114 forms a primary seal between the interiorsurfaces of the glass lites 104 and spacer 106. As shown in FIG. 2,sealant 114 is disposed in at least the corners between the spacer bodyand the glass lites. Sealant 114 can also extend entirely across thespacer between lites 104. Sealant 114 can be a made from any selfadhering material that has low gas and moisture permeability includingpolyisobutylene, saran, and epoxy adhesives. The sealants can provideimproved MVT characteristics, e.g., less than 10 g/m2/day, and improvedgas barrier capabilities. Examples of low MVT sealants includethermoplastic materials, such as hot-melt materials, e.g.,polyisobutylene (PIB). PIB materials typically have a low MVT value ofabout 1.0 g/m2/day or less. A majority of the volume of the sealant canbe made up of PIB.

FIG. 3 depicts a spacer discontinuity located at a corner of the unitwherein the ends 120 and 122 of spacer 106 abut or are closely spaced.This corner is ninety degrees. Patch 142 can be bent around the corneras it is applied, bent into a shape that matches the corner before thepatch is applied, or provided in a shape that matches the corner.Regardless of how tightly ends 120 and 122 are pressed together, thisdiscontinuity location creates a large risk for vapor intrusion intounit 102 and/or for gas loss from unit 102. For example, when argon isadded to unit 102 to increase its R value, the manufacturer needs toguard against the argon leaking out.

Before sealant 140 is added to channel 108, a patch 142 is applied overthe joint and pressed into place with pressure. Optionally, heat can beapplied either by preheating patch 142, by a heat gun that directs hotair to patch 142 and the spacer, by heating the glass lites 104 at thelocation of the discontinuity, or by a heated tool head 144 that appliesthe pressure to patch 142. Patch 142 can be applied over thediscontinuity of spacer 106 after spacer 106 is applied to one lite 104or after both lites 104 are secured to spacer 106. Heat is applied in anamount sufficient to raise that heated portion to a temperature aboveambient in the location where the patch is being applied. After patch142 is applied, sealant 140 is added to channel 108 to completely coverpatch 142.

Patch 142 includes a sealant layer 150 carried by a substrate 152. Thesealant is polyisobutylene-based (PIB-based) or an equivalent. Substrate152 is a solid flexible durable film with suitable barrier properties.Sealant layer 150 has a thickness of 2.54 mm (0.10 inch) and can be 2 mm(0.08 inch) or as thin as about 1 mm (0.04 inch). These thicknessesprovide enough sealant volume to be injected into the discontinuity andto wet out to both glass lites across the spacer width. When thepressure is applied to patch 142 when it is trapped between lites104—regardless of the application of heat—sealant 150 is injected intothe joint defined between ends 120 and 122 and forces sealant 150 toflow from glass edge to glass edge and into open spaces (voids) belowand adjacent to patch 142 thereby blocking pathways for gas diffusion ineither direction (inside-to-outside or outside-to-inside). The timeduration of the pressure applied to patch 142, with or withoutadditional heat, may be either brief or sustained as needed to achievethe injection of sealant 150 into the joint and the flow of the sealantfrom glass-to-glass and into all the open spaces (voids) below andadjacent to patch 142. Joint patch 142 itself carries enoughpolyisobutylene (PIB), or equivalent, sealant so that when pressure isapplied to patch 142 and sustained as needed, either with or withoutadditional heat, there is sufficient sealant to flow into the joint andessentially all of the spaces (voids) below and adjacent to patch 142and create a durable hermetic seal. FIG. 4 depicts first 160 and second162 tools that are used to apply pressure and the optional heat to patch142. Tool 160 is used for corner patches 142 while tool 162 is used forflat patches 142 that can be used over splices or other seal breachessuch as wires, capillary tubes, gas-fill holes, support fasteners. Eachtool 160 and 162 has a head that engages patch 142. The heads havewidths that are slightly narrower than the spacer between lites 104 sothat they may be used to apply a uniform controlled pressure and/or heatto the coated patch 142. The width of the tool head is about 2 mm lessthan the spacer width or gap between the two lites of glass. The spacercan have a width of 4.50 mm to 25.00 mm. If the patch is being appliedaround a corner, a tool 160 with a notch of about the same angle as thecorner can be used. If the joint is on a straight side, a straight tool162 can be used. If the breach is due to capillary tube or wireinsertion points, gas-fill holes or IG component fasteners, a customdesigned tool can be used.

The application of a suitable sealant-coated patch 142 using the novelcompression-injection method, with or without additional heat, has beenfound to be more likely than the known prior art method described aboveto produce a hermetic seal from glass-to-glass in an IG unit spacerjoint. The advantage of creating an effective joint seal is improved IGunit durability and thermal performance over the service life of the IGunit as well as a greater probability that test units will passcertified laboratory testing to industry standards such as EN1279 andASTM E2190. Test results from Argon permeation studies indicate that onunit builds where the only change was injection corner patch thatprecision was increased by a factor of 10 and level of argon permeationwas decreased by a factor five.

Patch 142 can be formed and applied manually or as part of an automatedIG assembly method. Exemplary description of method steps follow.

Joint Patch Application Sequence

(Largely Independent of IGU Construction Sequence and Gas Fill Method)

-   -   1. Cut the PIB, or equivalent, sealant-coated joint patch to the        proper width and length. The width of the patch should be        slightly less than the width of the spacer itself. A typical        patch length will be about 38.10 mm (1.5 inches) to 50.80 mm        (2.0 inches). If the IG unit is triple-glazed or        quadruple-glazed, the patch for each spacer joint should be cut        to size based on the width of the spacer in each airspace.    -   2. Protect the patch so both sides remain clean, undamaged and        free to adhere.    -   3. Position the properly sized coated joint patch over the joint        such that it is centered over the joint in both directions        (width and length).    -   4. With both lites of glass enclosing the airspace matched to        the spacer, apply pressure, with or without additional heat, to        the joint patch until the PIB or equivalent sealant has been        injected into the joint and has flowed into the voids below and        around the patch forming a continuous hermetic seal from glass        lite to glass lite. The use of a tool to assist with the        application of pressure and/or additional heat is recommended        but not required.

In an automated IG assembly method, patches 142 can be supplied in acontinuous strip of patch material which can be stored on a reel.Another semi-automated or manual option is “pick-and-place” where thepatch is precut to the desired width and length and spooled up on arelease liner. This varies by equipment manufacturer and can besemi-automated. Patches 142 can be formed by cutting the continuousstrip to the desired length as the patch is needed. One or both sides ofthe patch material can be protected with a release liner to limitcontamination of the sealant of the patch. In another configuration,patches 142 are carried by a reel on one release liner or between tworelease liners but each patch 142 is already cut to length and/or width.In both configurations, patches 142 can be positioned over the spacerjoint after the lites 104 are positioned on the spacer and a tool 160 or162 can be brought into contact with the patch to apply the pressureneeded to inject the sealant into the joint. In another configuration, aroller can be applied from one end of the patch to another to apply thepressure. As described above, the application of additional heat eitherto the joint, the patch and the joint, or just to the patch is anoptions. A heat gun may be used to apply the heat. The patch 142 isapplied and pressurized prior to the addition of the sealant 140 intothe sealant channel 108.

In the foregoing description, certain terms have been used for brevity,clearness, and understanding. No unnecessary limitations are to beimplied therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued. Moreover, the description and illustration of the inventionis an example and the invention is not limited to the exact detailsshown or described. Modifications and alterations of those embodimentswill be apparent to one who reads and understands this generaldescription. The present disclosure should be construed as including allsuch modifications and alterations insofar as they come within the scopeof the appended claims or equivalents thereof. Throughout thedescription and claims of this specification the words “comprise” and“include” as well as variations of those words, such as “comprises,”“includes,” “comprising,” and “including” are not intended to excludeadditives, components, integers, or steps.

1-22. (canceled)
 23. An insulating glazing unit comprising: first andsecond lites connected to a spacer having a spacer discontinuity; apatch having a substrate and a layer of patch sealant; the patchdisposed over the spacer discontinuity; a portion of the patch sealantbeing disposed in the discontinuity; and a sealant disposed over thesubstrate of the patch.
 24. The insulating glazing unit of claim 23,wherein the patch includes a solid substrate; the layer of patch sealantbeing directly connected to the solid substrate.
 25. The insulatingglazing unit of claim 23, wherein the patch sealant is continuousbetween the first and second lites.
 26. The insulating glazing unit ofclaim 23, wherein the first and second lites each have an outerperimeter edge; the spacer being disposed inwardly of outer perimeteredges of the first and second lites to define a channel; and the sealantbeing disposed in the channel.
 27. The insulating glazing unit of claim23, further comprising argon gas disposed between the first and secondlites inwardly of the spacer.
 28. The insulating glazing unit of claim23, wherein the patch is centered over the spacer discontinuity.
 29. Theinsulating glazing unit of claim 23, wherein the spacer is connected tothe first and second lites with a spacer adhesive.
 30. The insulatingglazing unit of claim 29, wherein the spacer adhesive is an acrylicadhesive.
 31. The insulating glazing unit of claim 23, wherein thespacer discontinuity is located at a spacer corner.
 32. The insulatingglazing unit of claim 23, wherein the patch sealant has a thicknessbetween 1 mm and 2.54 mm.
 33. The insulating glazing unit of claim 32,wherein the patch sealant includes polyisobutylene.
 34. The insulatingglazing unit of claim 33, wherein the substrate of the patch is a solidflexible film.
 35. An insulating glazing unit comprising: first andsecond lites connected to a spacer having a spacer discontinuity; and apatch having a substrate and a layer of patch sealant; the patchdisposed over the spacer discontinuity; a portion of the patch sealantbeing disposed in the discontinuity.
 36. The insulating glazing unit ofclaim 35, wherein the patch includes a solid substrate; the layer ofpatch sealant being directly connected to the solid substrate.
 37. Theinsulating glazing unit of claim 35, wherein the patch sealant iscontinuous between the first and second lites.
 38. The insulatingglazing unit of claim 35, wherein the first and second lites each havean outer perimeter edge; the spacer being disposed inwardly of outerperimeter edges of the first and second lites to define a channel; andthe sealant being disposed in the channel over the substrate of thepatch.
 39. The insulating glazing unit of claim 35, wherein the patchsealant has a thickness between 1 mm and 2.54 mm.
 40. The insulatingglazing unit of claim 39, wherein the patch sealant includespolyisobutylene.
 41. The insulating glazing unit of claim 40, whereinthe substrate of the patch is a solid flexible film.
 42. An insulatingglazing unit comprising: first and second lites connected to a spacerhaving a spacer discontinuity; the spacer discontinuity being located ata spacer corner; the first and second lites each having an outerperimeter edge; the spacer being disposed inwardly of outer perimeteredges of the first and second lites to define a channel; a patch havinga substrate and a layer of patch sealant; the patch disposed over thespacer discontinuity; a portion of the patch sealant being disposed inthe discontinuity; the patch sealant being continuous between the firstand second lites; and a sealant disposed in the channel over thesubstrate of the patch.
 43. The insulating glazing unit of claim 42,wherein the patch sealant has a thickness between 1 mm and 2.54 mm. 44.The insulating glazing unit of claim 43, wherein the substrate of thepatch is a solid flexible film.